Mobile communication apparatuses are widely used, and many users prefer to be able to customize the behaviour of their mobile communication apparatus. A feasible way to do this is to use themes. A theme in a mobile communication apparatus is a feature used to provide a preferred appearance to a user interface layout. A theme can affect characteristics of a layout, background color, fill and border characteristics of a field, as well as text attributes for labels and/or text. A mobile communication apparatus capable of presenting themes normally provides a set of themes which the user can select according to her preferences at the moment. However, there is always a demand for new features in mobile communication apparatuses. Therefore, there is a need for an improved ability for customization of mobile communication apparatuses.